Amateur astronomers from Shoalhaven Australia

Auriga

Abbreviation: Aur

Genitive: Aurigae

English: The Charioteer

Size Ranking: 21st

Area: 657 square degrees

Fully Visible: 90°N-34°S

Auriga, a large and prominent constellation which represents the driver of a horse drawn chariot; according to Greek legend he is Erichthonius, a legendry king of Athens and a skilled charioteer. However, mythology gives no explanation for his depiction in the sky with a goat and its kids being carried on his right arm. The goat is marked by the constellation’s brightest star, Capella, meaning ‘she-goat’, while the kids are depicted by ζAur and ηAur. In Greek and roman times, the charioteer’s right foot is represented by the star, once known as γAur, but now assigned to Taurus as βTau.

Auriga is to be located due north on the horizon, when, at the nominated time, the same viewing conditions to those advised in recent articles will be required.

Features of Interest:

αAur, named Capella, the she-goat, is the sixth brightest star in the sky at magnitude 0.08. It is a spectroscopic binary, consisting of two yellow giants orbiting every 104 days, although they do not eclipse each other, and is 42ly distant.

βAur, named Menkalinan, ‘shoulder of the charioteer’, being 82ly away, is an eclipsing variable of magnitude 1.9 consisting of two blue-white stars that orbit every 3.96 days, causing two dips in brightness of 0.1 magnitude on each orbit.

εAur is a white super-giant about 2000ly away and is an eclipsing binary of exceptionally long period. Normally it shines at magnitude 3.0, but every 27 years it sinks to magnitude 3.8 as it is eclipsed by a dark companion, remaining at minimum for a year. One theory is that its companion is a binary star enveloped in a disc of matter. Its next eclipse starts later this year.

ζAur is a famous eclipsing binary of contrasting stars: an orange giant orbited every 972 days by a smaller blue companion. During eclipses, the brightness drops from magnitude 3.7 to 4.0. It is 790ly away.

θAur is a blue white star of magnitude 2.6. It has a yellowish companion, separation 3.6”, PA 313°, requiring a steady night to achieve a difficult resolution. It is 173ly distant.

4 Aur is a double star, 159ly away, with component magnitudes of 5.0 and 8.1.

14Aur being 270ly away is a white star of magnitude 5.0 with a 7.9 magnitude companion, 82ly distant.

M36 is a small bright open cluster of about 60 stars, resolvable into stars using even smaller telescopes. It lies 3900ly away.

M37is the largest and richest of the clusters in Auriga, containing about 150 stars. Binocular viewing shows the cluster as a hazy, unresolved patch about two-thirds the width of the full Moon. Increased magnification should resolve it into a field of faint stardust, with a brighter orange star at the centre. It lies 4200ly away.

M38 is a large scattered cluster of about 100 faint stars, visible from lower magnifications as a noticeable cross-shape. Its distance is 3900ly.

NGC2281 is a binocular cluster of about 30 stars, 1500ly away. Through a telescope the stars appear to be arranged in a crescent, with four brighter stars forming a diamond shape.